Generally speaking, electrical-insulating packaging materials alias encapsulants are implemented to encapsulate IC chips inside semiconductor packages. As the development toward higher operation frequencies with smaller dimensions, IC chips are more vulnerable for EMI (electromagnetic interference) leading to signal transmission failure. Therefore, EMI shielding structures are often disposed inside semiconductor packages to avoid internal and external EMI. The existing EMI shielding structure can be divided into two major categories, one is EMI shielding sheets disposed inside semiconductor packages and encapsulated by the encapsulant as taught by Pollock et al. revealed in U.S. Pat. No. 6,365,960; the other is EMI shielding sheets or EMI shielding metal layers disposed on the top surface of the encapsulant as taught by Marcantonio et al. revealed in U.S. Pat. No. 5,294,826. However, the internally disposed EMI shielding sheets would have encapsulation issues and the externally disposed EMI shielding sheets/metal layers would have poor EMI shielding effects on the side surfaces and on the bottom surface of semiconductor packages and the issue of possible electrical short to external terminals.